Aerial mortar.



L. P." BARLOW..

AERIAL MORTAR.

APPLICATION men AUG-30,1916.

Patented Aug. 7 1917.

2 SHEETS-SHEET I.

INVEN TOR.

ATTORNEY L. P. BARLOW.

AERIAL MORTAR.

APPLKCATION men Aue.sq. 191s.

. Patented Aug. 7, 1917.

2 SHEETS SHEET 2.

UNITED STATES PATENT OFFICE.

LESTER P. BARLOW, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, BY MESNEASSIGNMENTS, 'I'O MARLIN ARMS CORPORATION, OF NEW YORK, N. Y., A COR-PORATION OF NEW YORK.

AERIAL MORTAR.

Specification of Letters Patent.

Patented Aug. 7, 1917.

Application filed August 30, 1916. Serial N 0. 117,578.

To all whom it may concern:

Be it known that I, LESTER P. BARLoW, a citizen of the United States,residing in the city and county of Philadelphia, State of Pennsylvania,have invented certain new and useful Improvements in Aerial Mortars, ofwhich the following is a specification.

My invention relates to what I may term aerial mortars, that is to say aconstruction which comprises a barrel, breech and firing mechanism, anda bomb or projectile contained'in or carried by the barrel, and adaptedto be expelled therefrom, the whole construction being adapted to bedropped from an aeroplane or other flying machine (or withmodifications, launched from a gun). The mortar as a whole is intendedto fall vertically, or at a desired angle, and embed itself in. theearth or other object struck. Arrangements are provided such that themortar as an entirety is brought to rest after entering the earth orobject struck a comparatively short distance, after which the bomb ortorpedo (or projectile) is expelled upwardly from the outer shell, or

- barrel, the object being to provide for the explosion of the bombabove the objedt struck and not, as particularly in the case of strikingthe earth, within the object struck, with the necessary result of aconfined explosion. Accordingly arrangements must be provided forcausing the explosion of the bursting charge within the bomb when thelatter has risen to a desired dis tance above the surface of the earthor object struck.

A device of this character is described in my application Serial No.104,209 aerialhand grenade, filed June 17, 1916. In the device describedtherein a delay charge, or fuse, is exploded when the striking nose ofthe device hits the earth, or object struck, this delay charge causingthe explosion of an 4 expelling charge after the downward motion of thegrenade has been arrested. Simultaneously with the upward expulsion ofthe bomb from the outer shell a second delay charge or fuse is exploded,which in turn explodes the bomb after the latter has risen a desireddistance above the object struck.

My present invention is in some respects a modification and in some animprovement upon the structure referred to. According to my presentinvention the explosion of the bursting charge in thebomb, after thelatter has been driven upwardly, is not caused by a delay fuse but bymechanical means comprising a flexible connection which is anchored atits lower end in the embedded portion of the mortar and connected at itsupper end to a relatively movable member in the bomb proper. When thisconnection has been extended to its full length the upward movement ofthe mechanism in the bomb to which the connection is secured isarrested, causing the concussion of a cap which serves to explode thebursting charge in the bomb. By this means the explosion is positivelycaused to take place at a definitely predetermined distance above theearth.

My present invention is also concerned with other improvements ofconstruction and combination of parts as will be hereinafter more fullyset forth and claimed in the accompanying claims.

In orderthat a clearer understanding of my invention may be hadattention is hereby directed to the accompanying drawings forming a partof this application and illustrating one construction whereby thedesired objects may be. accomplished.

Referring to the drawings Figure 1 represents in side elevation anaerial mortar embodying a form of my invention, Fig; 2 represents anenlarged central, vertical, sectional elevation through the mortar ofFig.

tional detail view of the lower portion of the barrel or gun-shell ofthe mortar withthe breech block secured therein and the bomb mounted inplace above the same, Fi 4 is a view similar to that of Fig. 2indicating, however, the position of the parts when the mortar has beendropped and plunged into the earth and when the bomb expelling chargehas shot the bomb almost clear of the gun-shell, and Figs. 5, 6 and 7are cross-sectional views shown respectively on lines 55, 6-6 and 77 ofF ig. 3.

Referring to the drawings, the numeral 1 designates a shell or casingwhich I term the gun-shell orbarrel, within which is contained the bombor torpedo 2. The gunshell is preferably a cylinder of sheet-metal tionsof the shell. At its lower or striking end the shell may be slotted orcut longitudinally so as to form what I term spreading flanges 4, anydesired number of which may be formed by slots 5 stamped out of the ma-Within the lower or forward end of theshell is inserted the block. 6which I term a breech block or gun breech mechanism preferably of theform indicated in Figs. 2 and 3. This breech ulock fills the interior ofthe lower end portion of the shell, is

cylindrical and is secured permanently .within the shell, preferably bybeing formed with circumferential grooves 7 into which the walls of theshell are forced or crimped by being formed into the circumferentialinternal beads 8.

The breech block 6 is formed with recessed portions of differentdiameters which will now be described. An enlarged cham ber 9 is formedwithin the upper portion of the breech block and within this iscontained the bomb expelling charge 10 of any pre ferred explosive. Thebomb or torpedo 2 is mounted above this chamber, as shown. Below chamber9 there is a cylindrical chamber 11 of less diameter'than chamber 9 andhaving a screw-threaded bore in which is mounted the externallyscrew-threaded recessed cylindrical member 12. The upper portion ofmember 12 extends into chamber 9, while the lower portion extends down-,wardly as far as does the chamber 11 in which it is screw-threaded.Below chamber 11 there is provided a cylindrical recess 13 of enlargeddiameter extending to the bottom of the lower tubular wall 14 of thebreech block.

The lower portion of cylindrical member 12 is recessed, as is shown at15, this recess extending into the base chamber 13 referred to andhaving atop circular wall 16. The penetrating nose piece 17 is mountedwithin base chamber 13 and has a cylindrical head portion 18 slidablymounted within the chamber 15 of member 12. The nose piece 17 ispreferably cylindrical for a portion of 'its length at the upper sectionthereof, as is shown at 19, where it is slidably fitted. within thetubular wall 14 of breech block 6. Nose piece 17 is preferably conicalfrom this point downwardly and extends outwardly some distance from thelower end of shell 1. A firing pin 20 is formed on the upper surface ofthe cylindrical portion 18 of the nose piece.

The nose piece is normally retained in the position represented in Figs.2 and 3 by the cotter pin 21 which is adapted to extend through a tube22 of copper or other rela-' tively soft metal. This tube extendsthrough alined bores which are drilled through the barrel 1, breechblock 3, and the depending annular wall of member 12, and also the headpiece' of nose piece 17. That is to say, when member 12 is screwed intoposition in the breech block, the opening referred to in member 12 isalined with the correspond.- ing opening through the breech block andthe outer shell and the nose piece 17 is slipped into position with theopening through the head 18 thereof in alinement with the said bores,after which the tube 22 i may 'be inserted through the alined openingsand cotter pin insertedthrough the tube. When the mortar is dropped froman aeroplane, or otherwise launched, the cotter pin 21 is firstwithdrawn. When now thenose piece 17 strikes the earth or other objectencountered, the soft copper tube 22 will be sheared through, drivingthe firing pin 20 into contact with the fuse-cap 23 to explode the cap.

Fuse-cap 23 is mounted in the lower wall of the charge cup 24 which isof cylindrical form with external screw-threads and is screwed into aninternally screw-threaded plurality of radial openings 30 extendingtherethrough connecting chamber 25 with the surrounding portion ofexplosive chamber 9 of breech block 6. A circular washer 31 ispreferably placed on top of the delay fuse 27 in chamber 26.

The result of the construction described is that when nose piece 17strikes an objectand is therefore driven upwardly through chamber 13,firing pin 20 explodes fuse-cap 23 and the latter in turn explodes thedelay fuse 27. The explosion of the lat- ,ter, however, does not takeplace for a moment, or until the downward movement of the grenade as awhole through the earth has been stopped or appreciably checked. Theproducts of explosion of fuse 27 pass radially through openings 29 andopenings 30 into the bomb expelling charge 10', exploding the latter anddriving bomb 2 upwardly.

.Bomb 2 contains a closed magazine chamber 32 which is filled with ahigh explosive charge designed to shatter the bomb when exploded. In theform of my invention illustrated, the chamber 32 extends downwardlythrough the lower end of the bomb or torpedo 2 and is internallyscrew-threaded at its lower portion, as is indicated at 33. Acylindrical member 34 having an externally screw-threaded periphery isscrewed into the screw-threads 33 to securely hold the same in positionat the lower end of the bomb. Member 34 has an axial cylindrical chamberextending through the same, the upper portion of which is internallyscrew-threaded, as is shown at 35, while the lower portion of the recesshas a smooth bore and is of less diameter than the upper portion, asshown at 36. A detonator 37 carrying a charge of detonating materialsuch as fulmmate of mercury 38 has an annular screw-threaded wall 39below the charge 38, the tubular wall 39 being firmly screwed into thescrew-threads of the upper portion of the chamber in member 34. Member34 carries a firing pin 40 which is integral with and extends axiallyupward from a bridge piece 41 which extends across the central openingthrough member 34, the ends of the bridge piece beingsecured in the sidewalls of member 34.

A member 42 is formed with a circular base portion 43 and a tubularupwardly extending portion 44. The circular flange or base 43 is adaptedto extend beneath the lower end of bomb 2 and member 34 therein and tobe seated, in the position of the parts shown in Figs. 2 and 3, on ashoulder 45 formed at the upper portion of chamber 9 .in breech block 6.The tubular upwardly extending portion 44 is slidably mounted in thecylindrical chamber 36 of member 34. The walls of cylindrical member 44are longitudinally slotted at diametrically opposite points, as inindicated at 46 in Fig. 6, for the passage therethrough of bridge piece41, so that member 42 with its tubular extension 44 may move up and downrelatively to the member 34 and bridge piece 41 secured thereto.

The upper-portion of tubular member 44 is internally screw-threaded toreceive a charge cup 47 containing a fuse-cap 48, the upper face ofcharge cup 47 being provided with openings 49 extending from the fusecap48 int-o the cylindrical space 50 below the detonating charge -38 andinclosed by the annular wall 39 of the detonator.

The bomb or torpedo 2 is normally secured in position on the breechblock 6 by a suitable detachable means such as a few turns ofscrew-thread 51 formed on the inner periphery of the tubular breechblock adjacent the upper end thereof. Preferably the bomb or torpedo isformed with a bottom portion 52 of reduced diameter which is mountedwithin the upper end of the breech block and secured thereto by thescrew-thread 51 as shown, the peripheral shoulder 53 thus formed on thebomb resting on the upper surface of the breech block, while the bottomsurface of the bomb rests on the base 43 of member 42, which in turnrests on the shoulder 45 of the breech block.

A flexible cord or wire cable is connected at its respective ends tomember 12 and member 42. For this purpose one end of cable '54 may beextended through a perforation in the top of member 12 into a recess 55therein, in which it is secured, recess 55 being closed by a washer 56at .its lower surface. Cable 54 may then be coiled about the upperportion of member 12 within chamber 9. The upper end of the cable mayconveniently be secured to member 42 by extending it through aperforation in the bottom of member 42, the end of the cable beingupset, or otherwise secured, as shown at 57 in the lower end of thecentral chamber of tubular member 44.

The operation of the device will now be apparent. When the mortarstrikes the earth, the engagement of member 42 with shoulder 45 preventsa premature contact between firing pin 40 and fuse cap 48. When,thereafter. the expelling charge 10 in chamber 9 has been exploded, asstated, the screw-threads 51 are stripped ofi and the bomb, togetherwith member 42, driven upwardly, as is shown in Fig. 4, until it hasbeen expelled from tube 1 a distance of say eight or ten feet when cable54 will be taut. During this interval member 42 will be pressed firmlyinto contact with bomb 2 by the presssure of the explosion in chamber 9.When cable 54 has become taut, however, the upward movement of member 42will be arrested, while the momentum of bomb 2 will continue to carrythe same up. Therefore bridge piece 41 which is secured to member 34 andthe bomb 2 will continue to rise with the result that firing pin 40contacts with fuse-cap 48 exploding the same. The explosion of fuse-cap48 explodes the detonating charge 38 which explodes the high explosivein magazine 32 in the bomb.

WVhile the construction described well illustrates my invention, itshould be understood that my invention is not strictly limited to theexact construction described. Thus in regard to the movements of thefiring pin 40 and the detonator 37, it is only essential that'a relativemovement should be caused to take place between these parts when theproper moment forthe explosion of the bomb has arrived, this relativemovement being such as to cause contact between them to explode thedetonator. It is not essential that the detonator should be permanentlymounted within the magazine chamber of the bomb. In my copendingapplication Serial No. 117,579, bombs or torpedoes, filed on August 30,1916, I have illustrated an arrangement by which the detonator isnormally mounted outside the magazine chamber of the bomb and is broughtinto the magazine chamber and into contact with the firing pin only whencable 54 has-become taut.

It will be noted that one of the advantages of my present constructionconsists in the continuous passageway extending from chamber 9 of thebreech block to the forward end, of the breech block, before member 12and nose piece 17 have been mounted in place. This continuous passagewaypermits chamber 9 to be filled with the explosive charge 10 from theforward end of the structure. The preferred arrangement of fuse-cup 24should also be noted, whereby the products of the explosion of the delaycharge 27 pass radially through openings 29 and 30 into the surroundingexplosive mixture in chamber 9.

In the claims, the member containing the bursting charge, which isadapted to be expelled from the outer barrel of the aerial mortar, willbe referred to as a bomb.

What I claim is 1. In an aerial mortar, the combinationof a barrel, ablock securedin the lower end thereof, having a chamber in the upperpart thereof, a nose-piece, a member resting on said block above saidchamber, a bomb, contaming a bursting charge, normally resting on saidmember, means in said chamberfor expelling said member and bomb from theupper end of the barrel when the nose-piece strikes an object, means forarresting the movement of said member at a predetermined point, andmeans brought lnto contact by the resultant relative movement betweensaid member and bomb to cause the explosion of said bursting charge,substantially as set forth.

2. In an aerial mortar, the combination of a barrel, a block secured inthe lower end thereof, having a chamber in the upper part thereof, anose-piece, a member resting on said block above said chamber, a bomb,containing a bursting charge, normally resting on said member, means insaid chamber for expellingsaid member and bomb from the upper end of thebarrel when the nose-piece strikes an object, said member having a partslidably fitting within the lower end of the bomb, a firing pin and fusecap, one of the same being carried by the bomb and the other by saidmember, and means for causing relative movement between said pin andfuse cap, to cause contact between the same to explode said burstingcharge, when said bomb has traveled a desired distance in its movementfrom the barrel, substantially as set forth.

3. In an aerial mortar, the combination of a barrel, a breech blocksecured in the lower end thereof, having an explosive chamber in theupper part thereof with an annular shoulder formed therein, a. flangedmember resting on said shoulder, a bomb, containing a bursting chargenormally resting on said member, means for causing an explosion in saidchamber to expel said member and bomb from the barrel, means forarresting the movement of said member at a predetermined oint, and meansbrought into contact by t e resultant relative movement between saidmember and bomb to cause the explosion of said bursting charge,substantially as set forth.

4. In an aerial mortar, the combination of a tubular barrel, a breechblock secured in the lower end thereof having a chamber in the upperpart thereof having a shoulder formed therein, a member resting on saidshoulder, a bomb, containing a bursting charge, normally resting-onsaid' member, said member having a part slidably fitting within thelower end of the bomb, means for exerting pressure in said chamber onthe lower face of said member to expel said member and bomb from thebarrel, means for arresting the movement of said member at apredetermined point, and means brought into contact by the resultantrelative movement between said member and bomb 'to cause the explosionof said bursting charge, substantially as set forth.

5. In an aerial mortar, the combination of a tubular barrel, a breechblock secured in the lower end thereof, having a chamber in the upperpart thereof having a shoulder formed therein, a member resting on saidshoulder, a bomb, containing a bursting charge, normally resting on saidmember,

. said member having a part slidably fitting within the lower end of thebomb, means for exerting pressure in said chamber on the lower face ofsaid member to expel said member and bomb from the barrel, aflexibleconnection between said breech block and said member, and meansbrought into contact, when'said connection becomes taut and relativemovement between said member and bomb is thereby caused, to cause'theexplosion of said bursting charge, substantially as set forth.

6. In an aerial mortar, the combination of a tubular barrel, a breechblock secured in the lower end thereof, having an explosive chamber inthe upper portion thereof, a

.bomb, containing an explosive charge, de-

tachably secured above said chamber, said block having an openingextending from said chamber through the lower end of the block, achambered member screw-threaded into said opening, and extendin intosaid explosive chamber, and a nose piece in the lower end of saidopening and extending into the interior of said member said nosepiecehavmg a firing pin and said member coacting fuse means, adapted toexplode material in saidtially as set forth.

. In an aerial morta explosive chamber, substanr, the combination of abomb having a magazine chamber, and an openin extendin the lovil er endof the from the same through bomb, a tubular member secured insaid-opening, a flanged member, having a tubular part slidably mountedsaid tubular member,

upwardly extending in the lower end of and a base flange adapted tocontact with the base of the I bomb, a bridge piece se cured to saidtubular pin, substantially as set Witnesses:

DYER SMITH, -M. S. GANG.

